This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A176449 #24 Jan 12 2024 17:29:35
%S A176449 7,16,34,70,142,286,574,1150,2302,4606,9214,18430,36862,73726,147454,
%T A176449 294910,589822,1179646,2359294,4718590,9437182,18874366,37748734,
%U A176449 75497470,150994942,301989886,603979774,1207959550,2415919102
%N A176449 a(n) = 9*2^n - 2.
%H A176449 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).
%F A176449 a(n) = 2*(a(n-1)+1) with a(0) = 7.
%F A176449 a(n) = 3*a(n-1) -2*a(n-2). G.f.: (7-5*x) / ((2*x-1)*(x-1)). - _R. J. Mathar_, May 02 2010
%F A176449 a(n) = 2*A052996(n+1) for n > 0. - _Bruno Berselli_ and _Vincenzo Librandi_, Aug 27 2010
%F A176449 a(n) = A033484(n+2) - A007283(n). - _M. F. Hasler_, Dec 11 2018
%e A176449 For n = 1, a(1) = 2*(7+1) = 16;
%e A176449 for n = 2, a(2) = 2*(16+1) = 34;
%e A176449 for n = 3, a(3) = 2*(34+1) = 70.
%p A176449 A176449:=n->9*2^n-2; seq(A176449(n), n=0..100); # _Wesley Ivan Hurt_, Nov 08 2013
%t A176449 Table[9*2^n-2, {n,0,100}] (* _Wesley Ivan Hurt_, Nov 08 2013 *)
%t A176449 LinearRecurrence[{3,-2},{7,16},40] (* _Harvey P. Dale_, Jan 12 2024 *)
%o A176449 (Magma) [9*2^n-2: n in [0..100]]
%o A176449 (PARI) apply( A176449(n)=9<<n-2, [0..99]) \\ _M. F. Hasler_, Dec 11 2018
%K A176449 nonn,easy
%O A176449 0,1
%A A176449 _Vincenzo Librandi_, Apr 18 2010
%E A176449 Edited by _M. F. Hasler_, Dec 11 2018